1. Field of the Invention
The present invention concerns a device for the measurement of magnetic properties of surfaces of bodies, in particular ferromagnetic substances, magnetic alloys, catalysts and spin glasses.
2. Discussion of Related Art
For the measurement of magnetic properties, in most cases a magnetic field externally applied to the body is required to align the magnetic domains in a definite preferred direction, i.e., the direction of the external magnetic field. With the detector of the present invention, magnetic properties of surfaces, for example, may be detected in a very simple manner without the use of an external magnetic field.
The methods considered efficient at the present time for the investigation of magnetic properties, for example, of surfaces, employ:
(a) the emission of polarized electrons by magnetic surfaces (by field emission, photoemission) and the detection of polarized electrons accelerated to approximately 100 KeV by Mott scattering (see: H. C. Siegmann in Phys. Rep. Phys. Lett. C (Netherlands), Vol. 17c, No. 2, pp. 37-76 (April, 1975)); and
(b) the capture of polarized electrons in ionic reflection and ion neutralization on surfaces and subsequent transfer of the electron spin polarization (ESP) by means of hyperfine interaction to produce core spin polarization, which may be used as a measurable value for the ESP (see: C. Rau in Comments on Solid State Physics, Vol. 9, No. 5 (1980)).
All of the methods have in common that a preferred direction in space by means of the application of an external magnetizing field is required for the alignment of the domains.